Radius wrinkles can form while manufacturing composite parts with curved or radiused corners or bends when sheets of uncured composite laminate are compressed on a male tool via vacuum bagging for curing thereof. As illustrated in FIGS. 1 and 2, when compressed from a first thickness T1 down to a second thickness T2, an excess of material forms primarily on outer-most plies of the composite laminate, resulting in wrinkling of those outer-most plies. Additionally, an undesirable phenomenon referred to as bridging can occur when sheets of uncured composite laminate are compressed on a female tool via vacuum bagging for curing thereof. As illustrated in FIGS. 3 and 4, when compressed from a first thickness T1 down to a second thickness T2, too little material exists on outer-most plies of the composite laminate, causing bridging or gaps between those outer-most plies.
Most techniques for avoiding or minimizing bridging and wrinkling in composite parts involve minimizing bulk factor during layup of the composite laminate, which can require substantial labor for compaction cycles and specialized layup techniques. Splices can be used to reduce bridging and wrinkling, but normally are not done on structural parts due to diminished structural integrity and/or added weight associated with the splices. A caul, bag-side assist, or pressure intensifier may be used to minimize bridging, but are not always effective and often result in mark-off on the resulting composite part or wrinkles at an edge where the semi-rigid caul ends.
Thus, there is a need for an improved method of manufacturing composite parts with curved or radiused corners or bends that minimizes wrinkles and bridging of the composite material.